WO 96/12445 describes a device, also referred to as obturator, for applying filler material, such as gutta percha or the like, to an endodontically prepared root canal or a tooth of a patient The device which Is disclosed in this patent generally comprises a core member, or tool, in the form of an elongated shaft of flexible material having a distal end portion and a proximal end portion. The distal end portion is covered with a sleeve of thermoplastic material. The sleeve is heated up before the obturator is inserted into the root canal. Thus, the thermoplastic sleeve becomes plastic and the thermoplastic sleeve will easily adapt to the anatomy of the root canal. However, due to irregularities in the shape of the canals or incomplete preparation of the canal, the thermoplastic sleeve does not always completely seal off all parts of the canal. A not completely sealed root canal can lead to irritations of the affected area or bacterial contamination leading to infection and failure of the root canal. Even when the thermoplastic material does seal the opening of the canal completely or almost completely, a gradual leaching out process from contact with tissue fluid will create more voids and poorer adaptation within the canal anatomy. These processes can lead to irritations, inflammations, and/or infected root canals which cause the patient discomfort and pain or even loss of the tooth.
Although the obturator with its sleeve of thermoplastic filler material has been a great step forward in improving the chances of completely filling a root canal, there still remains a small risk that a small part of the canal is not completely filled. Such small cavities can due to contact with tissue fluids create discomfort and pain to the patient.